I have a script working now to unmanage nodes, however cannot get anything to work to mute them. Please advise if anyone knows.
$swis = Connect-Swis -Credential $mycredentials -Hostname ....
$nodeid = Get-SwisData $swis "SELECT NodeID FROM Orion.Nodes WHERE SysName LIKE'dbprod1a'"
Invoke-SwisVerb $swis Orion.AlertSuppression SuppressAlerts @("N:$nodeid",[DateTime]::UtcNow) | Out-Null